The present invention relates generally to wave springs, and more particularly, to single-turn, round wire wave springs of circular cross-section that offer a variety of advantages over current flat wire wave springs.
Springs take many forms in the art. Some compression springs are made in a conventional manner in which a metal wire is wrapped around a mandrel in a spiral fashion to form a plurality of spring turns to form a spring of a desired length. These ordinary compression springs were not suitable for all purposes. Flat wire wave springs were developed in response for the need for specialty springs and were designed using flat wire to reduce the free height and operating height of a spring that was necessary to generate an appropriate spring force for a given application. Many such flat wire wave springs were developed for specialized applications. One example of such a wave spring is described in U.S. Pat. No. 4,901,987 issued Feb. 20, 1990 to the assignee of the present invention, in which a crest-to-crest wave spring is provided with circular flat end portions. The flat end portions permit the spring to seat better in its applications and the crest-to-crest arrangement provides for a softer and more precise spring rate.
Although the use of crest-to-crest wave springs in applications dictating higher force and deflection over the single turn flat wire wave spring, such springs are somewhat complicated and expensive to produce. Moreover, such springs require both greater free heights and operating heights which often negate their use in certain work applications. Additionally, the edge winding process has a tendency to possibly introduce an overall irregular, trapezoidal cross-sectional configuration shape that is difficult to maintain in its work position.
Other problems that may occur in flat wire, edge-wound wave springs involve the occasional production of deformed wave springs. Edge-winding of wave springs is a complex process that requires bending a flat wire about its longest cross-sectional axis, that is the full length of the flat wire is wound around a mandrel. This bending may sometimes cause compressive buckling along the interior edge of the flat wire, which is closest to the surface of the mandrel. Likewise, the exterior edge of the flat wire undergoes tension and often the exterior edge experiences a tensioning weakening along its exterior edge.
As such, a need currently exists for an improved wave spring that is more easily formed without buckling and which is less expensive to produce than a flat wire wave spring.
The present invention is directed to an improved wave spring that overcomes the aforementioned disadvantages.